Aikman, J. M., and R. F. Thorne. 1956. The Cayler Prairie: an ecological and taxonomic study of a northwest Iowa prairie. Proc. Iowa Acad. Sci. 63: 177–200.
Arthur, J. C. 1876. Contributions to the flora of Iowa: a catalogue of the phanerogamous plants. Charles City, Iowa, Intelligencer.
Arthur, J. C. 1877. Contributions to the flora of Iowa, No. 2. Proc. Davenport Acad. Nat. Sci. 2: 126.
Arthur, J. C. 1878. Contributions to the flora of Iowa, No. 3. Proc. Davenport Acad. Nat. Sci. 2: 258–261.
Arthur, J. C. 1882. Contributions to the flora of Iowa, No. 4. Proc. Davenport Acad. Nat. Sci. 3: 169–172.
Arthur, J. C. 1884a. Contributions to the flora of Iowa, No. 5. Proc. Davenport Acad. Nat. Sci. 4: 27–30.
Arthur, J. C. 1884b. Contributions to the flora of Iowa, No. 6. Proc. Davenport Acad. Nat. Sci. 4: 64–75.
Baker, R. G., C. A. Chumbley, P. M. Witinok, and H. K. Kim. 1990. Holocene vegetational changes in eastern Iowa. J. Iowa Acad. Sci. 97: 167–177.
Baker, R. G., D. G. Horton, H. K. Kim, A. E. Sullivan, D. M. Roosa, P. M. Witinok, and W. P. Pusateri. 1987. Late Holocene paleoecology of southeastern Iowa: development of riparian vegetation at Nichols Marsh. Proc. Iowa Acad. Sci. 92: 51–70.
Baker, R. G., L. J. Maher, C. A. Chumbley, and K. L. Van Zant. 1992. Patterns of Holocene environmental changes in the midwestern United States. Quaternary Res. 37: 379–389.
Baker, R. G., and K. L. Van Zant. 1978. The history of prairie in northwest Iowa: the pollen and macrofossil record. Pp. 8–11 in D. C. Glenn-Lewin and R. Q. Landers, eds., Proc. Fifth Midwest Prairie Conference, Iowa State Univ. Extension Serv., Ames.
Beal, E. O., and P. H. Monson. 1954. Marsh and aquatic angiosperms of Iowa. Univ. Iowa Studies Nat. Hist. 19(5): 1–95.
Beal, E. O., J. W. Wooten, and R. B. Kaul. 1982. Review of the Sagittaria engelmannia complex with environmental correlations. Syst. Bot. 7: 417–432.
Bessey, C. E. 1871. Contributions to the flora of Iowa. Iowa Agric. Coll. 4th Bienn. Rept., pp. 90–127.
Bettis, E. A., J. C. Prior, G. R. Hallberg, and R. L. Handy. 1986. Geology of the Loess Hills region. Proc. Iowa Acad. Sci. 93: 78–85.
Bishop, R. A. 1981. Iowa's wetlands. Proc. Iowa Acad. Sci. 88: 11–16.
Boot, D. H. 1901. Comparison of field and forest floras of Monona County, Iowa. Botanical Laboratory, Univ. of Iowa, Iowa City.
Boot, D. H. 1917. Plant studies in Lyon County, Iowa. Proc. Iowa Acad. Sci. 60: 82–85.
Boufford, D. E. 1982. The systematics and evolution of Circaea (Onagraceae). Ann. Missouri Bot. Gard. 69: 804–994.
Braun, E. L. 1950. Deciduous forests of eastern North America. Hafner Press, New York.
Brotherson, J. D. 1969. Species composition, distribution, and phytosociology of Kalsow Prairie, a mesic tallgrass prairie in Iowa. Ph.D. dissertation, Iowa State Univ., Ames.
Brown, M. E., and R. G. Brown. 1939. Preliminary list of the plants of the sand mounds of Muscatine and Louisa counties. Proc. Iowa Acad. Sci. 46: 167–178.
Cahayla-Wynne, R., and D. C. Glenn-Lewin. 1978. The forest vegetation of the Driftless Area, northeast Iowa. Am. Midi. Nat. 100: 307–319.
Carroll, S., R. L. Miller, and P. D. Whitson. 1984. Status of four orchid species at Silver Lake Fen complex. Proc. Iowa Acad. Sci. 91: 132–139.
Carter, J. L. 1960. The flora of northwestern Iowa. Ph.D. dissertation, Univ. of Iowa, Iowa City.
Carter, J. L. 1963. The flora of Cherokee County. Proc. Iowa Acad. Sci. 69: 60–70.
Christiansen, P. A. 1992. Distribution maps of Iowa prairie plants. Iowa Dept. of Transportation, Ames.
Clambey, G. K., and R. Q. Landers. 1978. A survey of wetland vegetation in north-central Iowa. Pp. 32–35 in D. C. Glenn-Lewin and R. Q. Landers, eds., Proc. Fifth Midwest Prairie Conference, Iowa State Univ. Extension Serv., Ames.
Clayton, W. D. 1968. The correct name of the common reed. Taxon 17: 168–169.
Coffey, V. J. The Scrophulariaceae of Iowa. M.S. thesis, Univ. of Iowa, Iowa City.
Coleman, V. W. 1950. The Liliaceae of Iowa. M.S. thesis, Univ. of Iowa, Iowa City.
Conard, H. S. 1938. The fir forests of Iowa. Proc. Iowa Acad. Sci. 45: 69–72.
Conard, H. S. 1951. Plants of Iowa. 7th ed. Iowa City.
Conard, H. S. 1952. The vegetation of Iowa. Univ. Iowa Studies Nat. Hist. 19(4): 1–166.
Cooperrider, T. S. 1959. The ferns and other pteridophytes of Iowa. Univ. Iowa Studies Nat. Hist. 20(1): 1–66.
Cooperrider, T. S. 1962. The vascular plants of Clinton, Jackson, and Jones counties, Iowa. Univ. Iowa Studies Nat. Hist. 20(5): 1–80.
Cratty, R. I. 1933. The Iowa flora: an annotated list of the ferns, fern allies and the native and introduced flowering plants of the state represented in the Iowa State College herbarium. Iowa State Coll. J. Sci. 7: 177–252.
Crawford, D. J. 1970. The Umbelliferae of Iowa. Univ. Iowa Studies Nat. Hist. 21(4): 1–36.
Crins, W. J., and P. W. Ball. 1983. The taxonomy of the Carex pensylvanica complex (Cyperaceae) in North America. Can. J. Bot. 61: 1692–1717.
Crist, A. M., and D. C. Glenn-Lewin. 1978. The structure of community and environmental gradients in a northern Iowa prairie. Pp. 57–64 in D. C. Glenn-Lewin and R. Q. Landers, eds., Proc. Fifth Midwest Prairie Conference, Iowa State Univ. Extension Serv., Ames.
Crum, G. H., and J. I. Knapp. 1976. The Elatinaceae in Iowa. Proc. Iowa Acad. Sci. 83: 63.
Curtis, J. T. 1959. The vegetation of Wisconsin. Univ. of Wisconsin Press, Madison.
D'arcy, W. G. 1978. Names in Agalinis for some plants that were called Gerardia and Virgularia (Scrophulariaceae). Ann. Missouri Bot. Gard. 65: 769–771.
Davidson, R. A. 1959. The vascular flora of southeastern Iowa. Univ. Iowa Studies Nat. Hist. 20(2): 1–102.
Davidson, R. A. 1960. Plant communities of southeastern Iowa. Proc. Iowa Acad. Sci. 67: 162–173.
Davis, R. J. 1966. The North American perennial species of Claytonia. Brittonia 18: 285–303.
Deevy, E. S., and R. F. Flint. 1957. Postglacial hypsithermal interval. Science 125: 182–184.
Dick-Peddie, W. A. 1955. Presettlement forest types in Iowa. Ph.D. dissertation, Iowa State Univ., Ames.
Dietrich, W., and P. H. Raven. 1976. An earlier name for Oenothera strigosa (Onagraceae). Ann. Missouri Bot. Gard. 63: 382–383.
Dorn, R. D. 1988. Chenopodium simplex, an earlier name for C. gigantospermum (Chenopodiaceae). Madrono 35: 162.
Dorr, L. J. 1990. A revision of the North America genus Callirhoe (Malvaceae). Mem. New York Bot. Gard. 56: 1–74.
Duritsa, M. F. 1983. A natural areas inventory of Black Hawk County, Iowa. M.S. thesis, Univ. of Northern Iowa, Cedar Falls.
Eilers, L. J. 1963. The vegetation of the glacial border during the Wisconsin maximum. Proc. Iowa Acad. Sci. 70: 60–64.
Eilers, L. J. 1965. The postglacial phytogeography of the Iowan Lobe. Proc. Iowa Acad. Sci. 72: 84–98.
Eilers, L. J. 1971. The vascular flora of the Iowan area. Univ. Iowa Studies Nat. Hist. 21(5): 1– 137.
Eilers, L. J. 1974. A flora of Brush Creek Canyon State Preserve. Proc. Iowa Acad. Sci. 81: 150–157.
Eilers, L. J. 1975. History of studies on the Iowa flora. Proc. Iowa Acad. Sci. 82: 59–64.
Eilers, L. J. 1979. BIOBANK, a computerized data storage and processing system for the vascular flora of Iowa. Proc. Iowa Acad. Sci. 86: 15–18.
Espenshade, E. B., ed. 1964. Goode's world atlas. 12th ed. Rand McNally Co., Chicago.
Farrar, D. R. 1985. Pteridophytes of Iowa's Loess Hills: adaptations to dry habitats. Proc. Iowa Acad. Sci. 92: 196–198.
Fay, M. J. 1951. The flora of Cedar County, Iowa. Proc. Iowa Acad. Sci. 58: 107–131.
Fay, M. J. 1953. The flora of southwestern Iowa. Ph.D. dissertation, Univ. of Iowa, Iowa City.
Fernald, M. L. 1953. Gray's manual of botany. 8th ed. American Book Co., New York.
Fitzpatrick, T. J., and M. F. L. Fitzpatrick. 1897. The flora of southern Iowa. Proc. Iowa Acad. Sci. 5: 134–173.
Freckmann, R. W. 1978. New combinations in Dichanthelium (Poaceae). Phytologia 39: 268–270.
Freese, E. L., and W. J. Piatt. 1991. Vascular flora of Arend's Kettle, Freda Haffner Kettlehole State Preserve, Dickinson County, Iowa. J. Iowa Acad. Sci. 98: 102–107.
Frest, T. J. 1981. Iowa Pleistocene snail. Final report on project SE-1–4 submitted to the U.S. Fish and Wildlife Service and Iowa Dept. of Natural Resources.
Fults, J. L. 1934. A botanical survey of Lee County, Iowa. Iowa State Coll. J. Sci. 8: 251–293.
Gabel, M. 1984. A biosystematic study of the genus Elymus (Gramineae: Triticae) in Iowa. Proc. Iowa Acad. Sci. 79: 140–146.
Gilly, C. L. 1946. The Cyperaceae of Iowa. Iowa State Coll. J. Sci. 21: 55–151.
Gilly, C. L. 1947. The flora of Iowa: a progress report based on past contributions. Proc. Iowa Acad. Sci. 54: 99–106.
Gilly, C. L., and M. E. MacDonald. 1936. Rare and unusual plants from southeastern Iowa. Proc. Iowa Acad. Sci. 43: 143–149.
Gilly, C. L., and M. E. MacDonald. 1947. A preliminary report on the flora of southeastern Iowa, Part 1. Proc. Iowa Acad. Sci. 54: 107–126.
Gilly, C. L., and M. E. MacDonald. 1948. Preliminary report on the flora of southeastern Iowa, Part 2. Proc. Iowa Acad. Sci. 55: 115–133.
Gleason, H. A., and A. Cronquist. 1963. Manual of vascular plants of northeastern United States and adjacent Canada. D. van Nostrand Co., New York.
Glenn-Lewin, D. C. 1976. The vegetation of Stinson Prairie, Kossuth County, Iowa. Proc. Iowa Acad. Sci. 83: 88–93.
Glenn-Lewin, D. C, R. H. Laushman, and P. D. Whitson. 1984. The vegetation of the Paleozoic Plateau, northeastern Iowa. Proc. Iowa Acad. Sci. 91: 22–27.
Goodman, G. J. 1939. Plants new to Iowa. Proc. Iowa Acad. Sci. 46: 105–106.
Goodman, G. J. 1942. Notes on Iowa plants. Proc. Iowa Acad. Sci. 49: 207–209.
Gould, F. W. 1974. Nomenclatural changes in the Poaceae. Brittonia 26: 59–60.
Gould, F. W., and C. A. Clark. 1978. Dichanthelium (Poaceae) in the United States and Canada. Ann. Missouri Bot. Gard. 65: 1088–1132.
Graham, S. A. 1979. The origin of Ammania X coccinea Rottboell. Taxon 28: 169–178.
Graham, S. A. 1985. A revision of Ammania (Lythraceae) in the western hemisphere. J. Arnold Arbor. 66: 395–420.
Grant, M. L. 1950. Dickinson County flora. Proc. Iowa Acad. Sci. 57: 91–129.
Grant, M. L., and R. F. Thorne. 1955. Discovery and description of a sphagnum bog in Iowa, with notes on the distribution of bog plants in the state. Proc. Iowa Acad. Sci. 62: 197–210.
Great Plains Flora Association. 1977. Atlas of the flora of the Great Plains. Univ. Press of Kansas, Lawrence.
Great Plains Flora Association. 1986. Flora of the Great Plains. Univ. Press of Kansas, Lawrence.
Greene, W., ed. 1907. Plants of Iowa: a preliminary list of the native and introduced plants of the state not under cultivation. Bull. State Hort. Soc: 1–264.
Guldner, L. F. 1960. The vascular plants of Scott and Muscatine counties. Davenport Publ. Mus. Publs. in Botany, No. 1.
Hallberg, G. R., E. A. Bettis, and J. C. Prior. 1984. Geologic overview of the Paleozoic Plateau region of northeastern Iowa. Proc. Iowa Acad. Sci. 91: 12–15.
Hartley, T. H. 1966. The flora of the Driftless Area. Univ. Iowa Studies Nat. Hist. 21(1): 1–174.
Hayden, A. 1940. A supplement to the catalogue of Iowa plants in the Iowa State College herbarium. Iowa State Coll. J. Sci. 14: 199–213.
Hayden, A. 1943. A botanical survey in the Iowa lake region of Clay and Palo Alto counties. Iowa State Coll. J. Sci. 17: 277–415.
Hayden, A. 1945. A second supplement to the catalogue of Iowa plants in the Iowa State College herbarium. Iowa State Coll. J. Sci. 19: 111–132.
Hayden, A. 1946. A progress report on the preservation of prairie. Proc. Iowa Acad. Sci. 53: 45–82.
Hinton, W. F. 1976. The systematics of Physalis pumila. Syst. Bot. 1: 188–193.
Hippler, M. I., Sr. 1951. An annotated bibliography of the taxonomic and ecological literature of the vascular plants of Iowa. M.S. thesis, Univ. of Iowa, Iowa City.
Hoch, P. C, and P. H. Raven. 1977. New combinations in Epilobium (Onagraceae). Ann. Missouri Bot. Gard. 64: 136.
Holte, K. E., and R. F. Thorne. 1962. Discovery of a calcareous fen complex in northwest Iowa. Proc. Iowa Acad. Sci. 69: 54–60.
Isely, D. 1962. Leguminosae of the north-central states, IV: Psoraleae. Iowa State J. Sci. 37: 103–162.
Isely, D. 1973. Leguminosae of the United States, I: subfamily Mimosoideae. Mem. New York Bot. Gard. 25(1): 1–152.
Isely, D. 1975. Leguminosae of the United States, II: subfamily Caesalpinioideae. Mem. New York Bot. Gard. 25(2): 1–128.
Isely, D. 1984. Astragalus L. (Leguminosae: Papilionoideae) II: species summary A-E. Iowa State J. Res. 59: 97–216.
Isely, D. 1985. Leguminosae of the United States, Astragalus L., III: species summary F-M. Iowa State J. Res. 60: 179–322.
Isely, D. 1990. Vascular flora of the southeastern United States, vol. 3, pt. 3, Leguminosae (Fabaceae). Univ. of North Carolina Press, Chapel Hill.
Johnson-Groh, C. L., and D. R. Farrar. 1985. Flora and phytogeographical history of Ledges State Park, Boone County, Iowa. Proc. Iowa Acad. Sci. 92: 137–144.
Johnson-Groh, C. L., D. Q. Lewis, and J. F. Shearer. 1987. Vegetation communities and flora of Dolliver State Park, Webster County, Iowa. Proc. Iowa Acad. Sci. 94: 84–88.
Jones, A. G. 1984. Nomenclatural notes on Aster (Asteraceae), II: new combinations and some transfers. Phytologia 55: 373–388.
Kartesz, J. T., and K. N. Gandhi. 1989. Nomenclatural notes for the North American flora, I. Phytologia 67: 461–467.
Kartesz, J. T., and K. N. Gandhi. 1990. Nomenclatural notes for the North American flora, II. Phytologia 68: 421–427.
Kartesz, J. T., and R. Kartesz. 1980. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Univ. of North Carolina Press, Chapel Hill.
Kellogg, G. E. 1946. The asters of Iowa. Proc. Iowa Acad. Sci. 53: 153–166.
Knapp, J. L. 1983. The erosional cycle of upland wetlands created by eolian sands. M.S. thesis, Univ. of Northern Iowa, Cedar Falls.
Koch, D. 1969. The Sioux Quartzite formation in Gitchie Manitou State Preserve. Development Series Report 8. State Preserves Advisory Board, Iowa City.
Kwang, Yao-Wen. 1951. The Polemoniales of Iowa (Convolvulaceae to Verbenaceae). M.S. thesis, Univ. of Iowa, Iowa City.
Lammers, T. G. 1980. The vascular flora of Starr's Cave State Preserve. Proc. Iowa Acad. Sci. 87: 148–158.
Lammers, T. G. 1983a. The vascular flora of Des Moines County, Iowa. Proc. Iowa Acad. Sci. 90: 55–71.
Lammers, T. G. 1983b. The vascular flora of Roggman Boreal Slopes State Preserve, Clayton County, Iowa. Proc. Iowa Acad. Sci. 90: 107–111.
Lammers, T. G., and A. G. Van Der Valk. 1977. A checklist of the aquatic and wetland vascular plants of Iowa, I: ferns, fern allies, and dicotyledons. Proc. Iowa Acad. Sci. 84: 41–88.
Lammers, T. G., and A. G. Van Der Valk. 1978. A checklist of the aquatic and wetland vascular plants of Iowa, II: monocotyledons. Proc. Iowa Acad. Sci. 85: 121–163.
Landolt, E. 1960. Biosystematics of the family of duckweeds (Lemnaceae), vol. 1. Veroff. Geobot. Inst. Eth, Stiftung Rubel. Zurich 70: 1–247.
Lehmann, J. W. 1983. The vascular flora of Dubuque County, Iowa. M.S. thesis, Univ. of Northern Iowa, Cedar Falls.
Lellinger, D. B. 1985. A field manual of the ferns and fern allies of the United States and Canada. Smithsonian Institution, Washington, D.C.
Lewis, W. H. 1961. Merger of the North American Houstonia and Oldenlandia under Hedyotis. Rhodora 63: 216–223.
Loomis, W. E., and A. L. McComb. 1943. Recent advances in the forest in Iowa. Proc. Iowa Acad. Sci. 51: 217–224.
McComb, A. L., and W. E. Loomis. 1944. Subclimax prairie. Bull. Torr. Bot. Club 71: 46–76.
Mohlenbrock, R. H. 1986. Guide to the vascular flora of Illinois. Southern Illinois Univ. Press, Carbondale.
Monson, P. H. 1959. Spermatophytes of the Des Moines Lobe in Iowa. Ph.D. dissertation, Iowa State Univ., Ames.
Morrill, J. B. 1953. Prairie flora of the Missouri River bluffs of western Iowa. M.S. thesis, Iowa State Univ., Ames.
Mutel, C. F. 1991. Fragile giants: a natural history of the Loess Hills. Univ. of Iowa Press, Iowa City.
Nekola, J. C. 1990. Rare Iowa plant notes from the R. V. Drexler herbarium. J. Iowa Acad. Sci. 97: 55–73.
Nicholson, D., and N. H. Russell. 1955. The genus Asclepias in Iowa. Proc. Iowa Acad. Sci. 62: 211–215.
Niemann, D. A. 1986. The distribution of orchids in Iowa. Proc. Iowa Acad. Sci. 93: 24–34.
Niemeier, P. E., and W. A. Hubert. 1984. The aquatic vascular flora of Clear Lake, Cerro Gordo County, Iowa. Proc. Iowa Acad. Sci. 91: 57–66.
Novacek, J. M. 1985. The Loess Hills of western Iowa: a problem in phytogeography. Proc. Iowa Acad. Sci. 92: 213–219.
Novacek, J. M., D. M. Roosa, and W. P. Pusateri. 1985. The vegetation of the Loess Hills landform along the Missouri River. Proc. Iowa Acad. Sci. 92: 192–212.
Ownbey, G. B., and T. Morley. 1991. Vascular plants of Minnesota, a checklist and atlas. Univ. of Minnesota Press, Minneapolis.
Pammel, L. H. 1899. The forest flora of Hardin County, Iowa. Iowa Geol. Survey Ann. Rept. 10: 306–313.
Pammel, L. H. 1924. The occurrence of Juniperus horizontalis in Floyd County near Rockford. Proc. Iowa Acad. Sci. 30: 297–300.
Parry, C. C. 1852. Systematic catalogue of plants of Wisconsin and Minnesota, Art. V. Pp. 606–622 in D. D. Owen, Report of a geological survey of Wisconsin, Iowa, and Minnesota. Lippencott, Grambo & Co., Philadelphia.
Pearson, J. A., and M. L. Leoschke. 1992. Floristic composition and conservation status of fens in Iowa. J. Iowa Acad. Sci. 99: 41–52.
Peck, J. H. 1976. The pteridophyte flora of Iowa. Proc. Iowa Acad. Sci. 83: 143–160.
Peck, J. H. 1980. Life history and reproductive biology of the ferns of Woodman Hollow, Webster County, Iowa. Ph.D. dissertation, Iowa State Univ., Ames.
Peck, J. H. 1982. Ferns and fern allies of the Driftless Area of Illinois, Iowa, Minnesota, and Wisconsin. Milwaukee Publ. Mus. Contr. in Biol, and Geol. 53: 1–140.
Peck, J. H. 1989. Additions to the Iowa pteridophyte flora, III. J. Iowa Acad. Sci. 96: 54–56.
Peck, J. H., and W. R. Buck. 1978. The Selaginella apoda complex in Iowa. Am. Fern J. 68: 29.
Peck, J. H., L. J. Eilers, and D. M. Roosa. 1978. The vascular plants of Fremont County, Iowa. Iowa Bird Life 48: 3–18.
Peck, J. H., B. W. Haglan, L. J. Eilers, D. M. Roosa, and D. Vander Zee. 1984. Checklist of the vascular flora of Lyon and Sioux counties, Iowa. Proc. Iowa Acad. Sci. 91: 92–97.
Peck, J. H., T. G. Lammers, B. W. Haglan, D. M. Roosa, and L. J. Eilers. 1981. A checklist of the vascular flora of Lee County, Iowa. Proc. Iowa Acad. Sci. 88: 159–171.
Peck, J. H., J. C. Nekola, and D. R. Farrar. 1989. Five pteridophytes new to Iowa. Amer. Fern J. 79: 28–29.
Peck, J. H., and D. M. Roosa. 1983. Bibliography of Iowa aquatic and wetland plant literature. Proc. Iowa Acad. Sci. 90: 72–77.
Peck, J. H., D. M. Roosa, and L. J. Eilers. 1980. A checklist of the vascular flora of Allamakee County. Proc. Iowa Acad. Sci. 87: 62–75.
Peck, J. H., and M. M. Smart. 1985. Bibliography to upper Mississippi River aquatic and wetland plant literature. Proc. Iowa Acad. Sci. 92: 78–84.
Peck, M. 1904. The flowering plants of Hardin County. Proc. Iowa Acad. Sci. 12: 193–214.
Phillips, M. N. 1977. Systematics of Saxifraga pensylvanica and a putative segregate species, S. forbesii (Saxifragaceae). M.S. thesis, Univ. of Wisconsin, Madison.
Pike, Z. M. 1810. Sources of the Mississippi and the western Louisiana Territory. March of America Facsimile Series No. 57. University Microfilms, Ann Arbor.
Plouffe, M. E. 1977. An autecological study of Betula papyrifera in the Iowa River greenbelt in Hardin County, Iowa, with notes on the vegetation. M.S. thesis, Iowa State Univ., Ames.
Pohl, R. W. 1966. The grasses of Iowa. Iowa State J. Sci. 40: 341–573.
Prior, J. C. 1991. Landforms of Iowa. Univ. of Iowa Press, Iowa City.
Pusateri, W. P., D. M. Roosa, and D. R. Farrar. 1993. Habitat and distribution of plants special to Iowa's Driftless Area. J. Iowa Acad. Sci. 100: 29–53.
Raven, P. H., W. Dietrich, and W. Stubbe. 1979. An outline of the systematics of Oenothera subsect. Euoenothera (Onagraceae). Syst. Bot. 4(3): 242–251.
Raven, P. H., and D. P. Gregory. 1972. A revision of the genus Gaura (Onagraceae). Mem. Torr. Bot. Club 23: 1–96.
Rickey, M. D. 1964. A floristic survey of Delaware County, Iowa. M.S. thesis, Univ. of Iowa, Iowa City.
Roosa, D. M. 1981. Marsh vegetation dynamics at Goose Lake, Hamilton County, Iowa: the role of historical, cyclical, and annual events. Ph.D. dissertation, Iowa State Univ., Ames.
Roosa, D. M., L. J. Eilers, and S. Zager. 1991. An annotated checklist of the vascular plant flora of Guthrie County, Iowa. J. Iowa Acad. Sci. 98(1): 14–30.
Roosa, D. M., M. J. Leoschke, and L. J. Eilers. 1989. Distribution of Iowa's endangered and threatened vascular plants. Dept. of Nat. Resources, Des Moines.
Roosa, D. M., and J. H. Peck. 1986. Annotated bibliography of Iowa prairie literature. Proc. Iowa Acad. Sci. 93: 54–69.
Rosburg, T. R. 1992. A new record for falcate spurge in the midwest. Prairie Nat. 24(1): 41–42.
Salsbury, N. E., and J. C. Knox. 1969. Glacial landforms of the Big Kettle locality, Dickinson County, Iowa. Development Series Report 6. State Preserves Advisory Board, Iowa City.
Sanders, D. R. 1968. Vegetation of slope forests along the Des Moines River. Proc. Iowa Acad. Sci. 75: 78–84.
Scholtes, W. H. 1955. Properties and classification of the paha-derived soils in northeastern Iowa. Iowa State Coll. J. Sci. 30: 163–209.
Sears, P. 1942. Xerothermic theory. Bot. Rev. 8: 708–736.
Sheviak, C. 1977. A new species of Spiranthes from the grasslands of central North America. Bot. Mus. Leafl. Harvard Univ. 23: 285–297.
Sheviak, C, and M. L. Bowles. 1986. The prairie fringed orchids: a pollinator-isolated species pair. Rhodora 88: 267–290.
Shimek, B. 1896. The flora of the Sioux Quartzite in Iowa. Proc. Iowa Acad. Sci. 4: 72–77.
Shimek, B. 1899. The flora of Lyon County. Iowa Geol. Surv. Ann. Rept. 10: 157–184. Bull. Lab. Nat. Hist. Univ. Iowa 5(2): 145–170.
Shimek, B. 1910. The geology of Harrison and Monona counties, Iowa. Iowa Geol. Surv. Ann. Rept. 20: 271–485.
Shimek, B. 1915. Early Iowa locality records. Proc. Iowa Acad. Sci. 22: 105–119.
Shimek, B. 1917. The sand flora of Iowa. Bull. Lab. Nat. Hist. Univ. Iowa 7(4): 6–24.
Shimek, B. 1924. The prairie of the Mississippi River bluffs. Proc. Iowa Acad. Sci. 31: 205– 212.
Shimek, B. 1948. (H. S. Conard, ed.). The plant geography of Iowa. Univ. Iowa Studies Nat. Hist. 19(4): 1–178.
Smith, D. D. 1981. Iowa prairie: an endangered ecosystem. Proc. Iowa Acad. Sci. 88: 7–10.
Smith, P. E., and R. V. Bovbjerg. 1958. Pilot Knob bog as a habitat. Proc. Iowa Acad. Sci. 65: 546–553.
Spence, W. L. 1959. The Salicaceae of Iowa. M.S. thesis, Univ. of Iowa, Iowa City.
State Planning Board. 1925. The Iowa twenty-five-year plan. Des Moines.
Thompson, C. A., E. A. Bettis, and R. G. Baker. 1992. Geology of Iowa fens. J. Iowa Acad. Sci. 99: 53–59.
Thomson, G. W., and H. G. Hertel. 1981. The forest resources of Iowa in 1980. Proc. Iowa Acad. Sci. 88: 2–6.
Thorne, R. F. 1953. Notes on rare Iowa plants. Proc. Iowa Acad. Sci. 60: 260–274.
Thorne, R. F. 1954. Present status of our knowledge of the vascular flora of Iowa. Proc. Iowa Acad. Sci. 61: 177–183.
Thorne, R. F. 1955. Flora of Johnson County, Iowa. Proc. Iowa Acad. Sci. 62: 155–227.
Thorne, R. F. 1956. Notes on rare Iowa plants, II. Proc. Iowa Acad. Sci. 63: 214–227.
Thorne, R. F. 1964. Relict nature of the flora of White Pine Hollow Forest Preserve, Dubuque County, Iowa. Univ. Iowa Studies Nat. Hist. 20(2): 1–33.
Tuttle, F. M. 1919. Flora of Mitchell County. Proc. Iowa Acad. Sci. 26: 269–299.
Ugarte, E. 1987. The hill prairies of northeast Iowa: vegetation and dynamics. Ph.D. dissertation, Iowa State Univ., Ames.
United States Department of Agriculture. 1941. Climate and man: yearbook of agriculture. U.S. Govt. Printing Office, Washington, D.C.
United States Department of Agriculture. 1982a. National list of scientific plant names, vol. 1: list of plant names. U.S. Govt. Printing Office, Washington, D.C.
United States Department of Agriculture. 1982b. National list of scientific plant names, vol. 2: synonymy. U.S. Govt. Printing Office, Washington, D.C.
Van Bruggen, T. 1958. The flora of south-central Iowa. Ph.D. dissertation, Univ. of Iowa, Iowa City.
Van Bruggen, T. 1985. The vascular plants of South Dakota. 2nd ed. Iowa State Univ. Press, Ames.
Van Der Linden, P., and D. R. Farrar. 1984. Forest and shade trees of Iowa. Iowa State Univ. Press, Ames.
Van Der Valk, A. G. 1975. Floristic composition and structure of fen communities in north-west Iowa. Proc. Iowa Acad. Sci. 82: 109–117.
Vander Zee, D. 1979. The vascular flora of Gitchie Manitou State Preserve. Proc. Iowa Acad. Sci. 86: 66–75.
Van Norman, K. 1987. The vascular flora of Black Hawk County, Iowa. M.S. thesis, Univ. of Northern Iowa, Cedar Falls.
Volker, R., and S. G. Smith. 1975. Changes in the aquatic vascular flora of Lake East Okoboji in historic times. Proc. Iowa Acad. Sci. 72: 65–72.
Voss, E. G. 1966. Nomenclatural notes on monocots. Rhodora 68: 435–463.
Voss, E. G. 1972. Michigan flora, Part 1: gymnosperms and monocots. Cranbrook Institute of Science, Bloomfield Hills, Mich.
Voss, E. G. 1985. Michigan flora, Part 2: dicots (Sauraceae-Cornaceae). Cranbrook Institute of Science, Bloomfield Hills, Mich.
Wagenknecht, B. L. 1954. The flora of Washington County, Iowa. Proc. Iowa Acad. Sci. 61: 184–204.
Wagner, W. L. 1983. New species and combinations in the genus Oenothera (Onagraceae). Ann. Missouri Bot. Gard. 70: 194–196.
Walker, P. H. 1966. Postglacial environments in relation to landscape and soils on the Cary Drift, Iowa. Iowa Agric. Exp. Stn. Res. Bull. 549: 838–875.
Webber, J. M., and P. W. Ball. 1979. Proposals to reject Carex rosea and Carex radiata of eastern North America (Cyperaceae). Taxon 28: 611–616.
Webber, J. M., and P. W. Ball. 1984. The taxonomy of the Carex rosea group (section Phaestoglochin) in Canada. Can. J. Bot. 62: 2058–2073.
Welsh, S. L. 1960. Legumes of the north-central states: galegeae. Iowa State J. Sci. 35: 111–250.
Wemple, D. K. 1970. Revision of the genus Petalostemon (Leguminosae). Iowa State J. Sci. 45: 1–102.
White, J. A., and D. C. Glenn-Lewin. 1984. Regional and local variation in tallgrass prairies of Iowa and Nebraska. Vegetation 57: 65–78.
Wilson, B. L. 1992. Checklist of the vascular flora of Page County, Iowa. J. Iowa Acad. Sci. 99: 23–33.
Wilson, B. L. 1993. Some significant Iowa plant records from the herbarium of University of Nebraska at Omaha. J. Iowa Acad. Sci. 100: 87–89.